The present invention relates to a method for winding synthetic fibers, a synthetic fiber winding apparatus, and a method for using a yarn package.
In more detail, the present invention relates to a technique for winding a yarn around a yarn winding bobbin without winding the initially straight-wound yarn tail bunch destined to be wasted later, positioned outside said yarn package, for getting rid of the tail bunch removing work, at a high successful bobbin-to-bobbin yarn transfer rate, and a technique incidental to said technique, for forming a yarn tail (transfer tail) with a proper length without splitting the tail, furthermore a technique for preventing the yarn end of a wound yarn package from slipping from the surface of the wound yarn package, and, in addition, a technique for carrying out the tail splicing work simply when using the package (for weaving or yarn processing, etc.).
A general winding machine with a mechanism for automatically transferring yarns from yarn winding bobbins to other yarn winding bobbins is described below in reference to FIGS. 1 and 2, and 3 through 7.
FIG. 1 is a schematic front view showing a multiple-yarn winding machine. FIG. 2 is a schematic side view showing a multiple-yarn winding machine. FIGS. 3 to 7 are schematic drawings expressing the action of automatic transfer of one yarn from a wound yarn package to an empty bobbin in time series. A winding machine 1 is composed of a turret plate 3 rotatably installed in a machine casing, two spindles 4 rotatably installed on the turret plate 3, a traverse fulcrum guide 20 for directing the yarn to a traverse device 5 installed above one of the spindles 4, yarn winding empty bobbins 16 mounted around the spindle 4, a contact pressure roller 6 for giving a predetermined face pressure to the yarns wound around the bobbins while being kept in contact with them, an upper yarn transfer mechanism 7 provided above the contact pressure roller 6, a yarn passage control mechanism 8 provided between the two spindles 4 for controlling the yarn passages when the yarns are transferred from wound yarn bobbins 17 to the empty bobbins 16, and a lower yarn transfer mechanism 12 provided between the empty bobbins 16 and the yarn passage control mechanism 8 for winding the yarns around the empty bobbins 16. The upper yarn transfer mechanism 7 is composed of yarn shift guides 9 moving in the traverse direction of a traverse guide for shifting the yarns outside the respective regular traverse areas to tail bunching positions and tail winding positions, and a drive source (not illustrated) for these actions. The yarn passage control mechanism 8 is composed of a yarn passage control guide 10 for controlling the yarn passages lest the yarns should contact the peripheral surfaces of the empty bobbins when the empty bobbins 16 at the standby position move to the winding position, and surface yarn bunching guides 11 for guiding the yarn passages toward the surface yarn bunching positions on the surfaces of the yarns wound around the fully wound packages 17.
The lower yarn transfer mechanism 12 is composed of initial winding guides 13 for guiding the yarns running between the yarn shift guides 9 and the yarn passage control guide 10 into contact with the peripheral surfaces of the empty bobbins 16 and moving the yarns in the axial direction of the empty bobbins 16 to let yarn holding portions 23 provided in the empty bobbins 16 hold the yarns, and arms 13xe2x80x2 (not illustrated) for actuating the initial winding guides 13 between the standby position and the winding position.
When the winding machine as mentioned above is used to change the yarns from the wound yarn packages 17 to the empty bobbins 16, the turret plate 3 is at first rotated 180 degrees clockwise, to move the wound yarn packages 17 at the winding position to the standby position, and to move the empty bobbins 16 at the standby position to the winding position.
At this time, as shown in FIG. 3, the yarn passage control guide 10 of the yarn passage control mechanism 8 is interlocked with the rotation of the turret 3 (not illustrated), to disengage the yarns from the traverse guide (not illustrated) and controls and supports the yarn passages lest the yarns should contact the peripheral surfaces of the empty bobbins 16.
Then, as shown in FIG. 4, the yarn shift guides 9 of the upper yarn transfer mechanism 7 carry the yarns outside the respective regular traverse areas, and the surface bunching guides 11 of the yarn passage control mechanism 8 let the yarns travel toward the surface bunching positions on the yarn windings of the wound yarn packages 17.
Then, as shown in FIG. 5, the initial winding guides 13 of the lower yarn transfer mechanism 12 (not illustrated) move into the space between the empty bobbins 16 and the yarn passage control mechanism 8, and as a result, the running yarns controlled in their passages by the yarn shift guides 9 of the upper yarn transfer mechanism (not illustrated) and the surface bunching guides 11 of the lower yarn transfer mechanism 8 are brought into contact with the peripheral surfaces of the empty bobbins 16 by the initial winding guides 13 and are moved in the axial direction of the empty bobbins 16, being introduced into and held by the yarn holding portions 23 provided in the circumferential direction of the empty bobbins 16 at the ends on one side of the empty bobbins 16. If the yarns are held, since both the fully wound packages 17 and the empty bobbins 16 rotate in the yarn winding direction, the yarns are cut in the space between the wound yarn packages 17 and the empty bobbins 16, and are transferred from the wound yarn packages 17 to the empty bobbins 16.
Then, as shown in FIG. 6, since the yarns are guided to shift toward the tail bunching positions of the empty bobbins by the yarn shift guides 9, the yarns coming out of the yarn holding portions move on to the peripheral surfaces of the empty bobbins 16, to form tail bunches at the predetermined winding positions.
Then, as shown in FIG. 7, after predetermined lengths of tail bunches have been wound, as the yarn shift guides 9 return toward the opposite ends of the bobbins, the yarns move toward the centers of the traverse areas while forming their tails, and are taken over by the traverse guide (not illustrated), to be wound in traverse.
As described above, in the automatic bobbin-to-bobbin yarn transfer according to the above mentioned conventional winding method and apparatus, after the yarns have been transferred to the empty bobbins, the yarn shift guides 9 of the upper yarn transfer mechanism 7 which support the yarns at the tail bunching positions against the force to move the yarns toward the centers of the traverse areas cause the yarns held by the empty bobbins 16 to be wound right under the yarn shift guides 9, to form tail bunches without fail. As a result, the formed tail bunches must be removed later, and this has been an extra burden of working.
Apart from the above apparatus, Japanese Patent Laid-Open (Kokai) No. Sho62-280172, Japanese Patent Publication (Kokoku) No. Sho57-36233 and Japanese Patent Laid-Open (Kokai) No. Hei6-321424 propose other turret type automatic winding machines, but all of these machines have the same problem as described above, since the yarn is supported against the force to move the yarn toward the center of the traverse area after it has been transferred to an empty bobbin, a tail bunch is formed without fail.
On the other hand, a winding apparatus without forming the tail bunch proposed in Japanese Patent Laid-Open (Kokai) No. Sho54-114674 is known.
However, with this apparatus, the yarn passage for introducing a yarn into a yarn holding groove extending in the circumferential direction in the surface of an empty bobbin is oblique to the yarn holding groove. As a result, the yarn cannot be reliably held, and it is difficult to achieve a high successful bobbin-to-bobbin yarn transfer rate for a variety of yarns different in physical properties and thickness.
To avoid these problems, it is proposed to form a groove oblique to a yarn fastener which supports the yarn at a position downstream of an empty bobbin when the yarn is introduced into the groove, or to move the spindle at the standby position in parallel to the spindle axis for letting the winding width of the wound yarn package reaching the standby position come right under the yarn holding groove without using the yarn fastener. These methods allow the yarn passage for introducing the yarn into the yarn holding groove to be kept in parallel to the yarn holding groove. However, the method of forming a groove oblique to a yarn fastener has a problem that since the frictional force generated at the oblique groove portion lowers the winding tension, the successful bobbin-to-bobbin yarn transfer rate is lowered, and the method of moving the spindle has a problem that the equipment becomes complicated to raise the equipment cost greatly.
Furthermore, even if the yarn passage for introducing the yarn into the yarn holding groove is kept in parallel to the yarn holding groove by either of the above methods, there is a problem that the tail of the yarn is loosened, in another word, split into single filaments, instead of being kept integral as a multi-filament. The reason why the tail of the yarn is split is that since the held yarn is immediately wound in the direction reverse to the running direction, the component single filaments become different from each other in tension, and that since there is no tail bunch, the tail dispersed in tension begins to be immediately wound. A package split at the tail has a problem that tail splicing work becomes difficult.
Moreover, though the freedom from the tail bunch does not require the work of removing the tail bunch later, the winding end of the wound yarn package slips from the surface of the wound yarn package, to be wound around an end of the bobbin. So the yarn wound around the bobbin end must be removed later, and after all, the working load is not reduced disadvantageously.
A first object of the present invention is to provide a method for winding synthetic fibers around a yarn winding empty bobbin, without forming the initially straight-wound yarn tail bunch to be wasted later, positioned outside the package, at a high successful bobbin-to-bobbin yarn transfer rate for a variety of yarns different in physical properties and thickness, for getting rid of the work of removing the tail bunch later, while assuring a stable winding process.
A second object of the present invention, in addition to the first object, is to provide a method for winding synthetic fibers, without causing the tail of a yarn to be split loosely into single fibers while allowing the stable and easy formation of a yarn tail with a length suitable for the tail splicing work of various kinds of yarns under various service conditions. Thus, the tail splicing work for using the package (for weaving or yarn processing, etc.) can be effected efficiently, and the present invention is intended to provide a method for winding synthetic fibers which allows the tail splicing work to be effected efficiently.
A third object of the present invention is to provide a method for winding synthetic fibers, which allows winding as a wound yarn package unlikely to cause the end of the yarn winding of the wound yarn package to slip from the surface of the wound yarn package. It is intended to provide a method for winding synthetic fibers, which can reduce the later work of removing the yarn end slipping from the surface and wound around an end of the bobbin.
A fourth object of the present invention is to provide a method, which allows the tail splicing work for using a package (for weaving, yarn processing, etc.) to be effected simply.
The method for winding a yarn of the present invention to achieve these objects is constituted as follows.
The present invention provides a method for winding synthetic fibers, in which a yarn is wound around an empty bobbin using a yarn winding apparatus composed of a traverse fulcrum guide for winding the yarn, a traverse device for traversing the yarn before winding it, a contact pressure roller for giving a predetermined face pressure to the wound yarn in contact with it, two spindles alternately used for winding the traversed yarn, a moving device for moving the spindles for transferring the yarn continuously from the spindle on the winding side to the spindle on the standby side, and a yarn transfer device for introducing the yarn into a yarn holding portion for holding the yarn, wherein said yarn transfer device is composed of an upper yarn transfer mechanism provided upstream of the empty bobbin mounted around the spindle on the winding side, a lower yarn transfer mechanism provided downstream, and a yarn passage control mechanism for controlling the yarn passage of the yarn extending to the wound yarn package moved to the standby side, comprising the steps of shifting the yarn outside the regular traverse area, to keep it almost parallel to the yarn holding portion by the upper yarn transfer mechanism and the lower yarn transfer mechanism; moving the yarn to the yarn holding portion by at least either of the upper yarn transfer mechanism and the lower yarn transfer mechanism, allowing the yarn to be held and cut by the yarn holding portion; allowing the holding point of the yarn to be moved in the rotating direction of the empty bobbin reverse to the running direction of the yarn; allowing the yarn to be automatically disengaged from the upper yarn transfer mechanism; moving the yarn toward the center of the traverse without forming the initially straight-wound yarn tail bunch; and starting regular winding when the yarn is engaged with the traverse guide. The present invention also provides a method for winding synthetic fibers, wherein the lower yarn transfer mechanism is an initial winding guide for bringing the yarn controlled by the upper yarn transfer mechanism and the yarn passage control mechanism into contact with the peripheral surface of the empty bobbin, and moving the yarn in the axial direction of the empty bobbin, to let the yarn holding portion hold the yarn. In more detail, the present invention provides a method for winding synthetic fibers, wherein the upper yarn transfer mechanism is composed of a yarn shift guide for shifting the yarn outside the regular traverse area, to let another guide to keep it, and returning to its home position, and a yarn keep guide for temporarily keeping the shifted yarn.
The yarn winding apparatus of the present invention to achieve the above objects is constituted as follows.
The present invention provides a synthetic fiber winding apparatus, in which a yarn is wound around an empty bobbin using a yarn winding apparatus composed of a traverse fulcrum guide for winding the yarn, a traverse device for traversing the yarn before winding it, a contact pressure roller for giving a predetermined face pressure to the wound yarn in contact with it, two spindles alternately used for winding the traversed yarn, a moving device for moving the spindles for transferring the yarn continuously from the spindle on the winding side to the spindle on the standby side, and a yarn transfer device for introducing the yarn into a yarn holding portion for holding the yarn, wherein said yarn transfer device is composed of an upper yarn transfer mechanism provided upstream of the empty bobbin mounted around the spindle on the winding side, a lower yarn transfer mechanism provided downstream, and a yarn passage control mechanism for controlling the yarn passage of the yarn extending to the wound yarn package moved to the standby side, characterized in that the yarn is moved outside the regular traverse area, to be kept almost parallel to the yarn holding portion by the upper yarn transfer mechanism and the lower yarn transfer mechanism, and moved to the yarn holding portion by at least either of the upper yarn transfer mechanism and the lower yarn transfer mechanism, to be held and cut by the yarn holding portion, that the holding point of the yarn is allowed to move in the rotating direction of the empty bobbin reverse to the running direction of the yarn, that the yarn is allowed to be automatically disengaged from the upper yarn transfer mechanism, and is moved toward the center of the traverse without forming the initially straight-wound yarn tail bunch, and that when the yarn is engaged with the traverse guide, regular winding is started. The present invention also provides a synthetic fiber winding apparatus, wherein the lower yarn transfer mechanism is an initial winding guide for bringing the yarn controlled by the upper yarn transfer mechanism and the yarn passage control mechanism into contact with the peripheral surface of the empty bobbin, and moving the yarn in the axial direction of the empty bobbin, to let the yarn holding portion hold the yarn. In more detail, the present invention provides a synthetic fiber winding apparatus, wherein the upper yarn transfer mechanism is composed of a yarn shift guide for shifting the yarn outside the regular traverse area, to let another guide keep the yarn kept, and returning to its home position, and a yarn keep guide for temporarily keeping the shifted.